This invention relates to an improved coupler for releasably connecting a prosthetic device such as an artificial leg or arm to a sleeve which receives the stump of an amputee's limb and has a projecting locking stud, for example, as disclosed in U.S. Pat. No. 5,376,129. As illustrated in FIGS. 9-11 of this patent, it is known to have an attachment device or coupler which uses a retractable release stem having a wedge-shaped inner end portion or pawl for engaging one of a plurality of grooves formed within the locking stud projecting from the sleeve. This general form of attachment device or coupler is made by the inventor of the present invention and sold by Prosthetic Design, Inc. of Clayton, Ohio under the trademark PDI. This company also sells another coupler manufactured by the inventor of the present invention and wherein the pawl is connected by a pivotal lever to the release stem so that the pawl is retracted to a released position when the stem is pushed inwardly. It is also known to retain the sleeve within the socket by means of a suction coupler, for example, of the type shown in U.S. Pat. No. 5,662,715 and U.S. Pat. No. 5,702,489 which disclose couplers made by the inventor of the present invention for the Assignee of the patents.
It has been found desirable to provide a prosthetic attachment device or coupler which provides the amputee user with a means for locking the coupler so that it may not be accidentally released, for example, by accidentally pushing or pulling the actuator stem. It has also been found desirable to provide a coupler which may be easily converted and assembled to provide an actuator stem which may be pushed to release and/or pulled to release and/or rotated to release the locking stud from the coupler. In addition, the coupler should provide for conveniently receiving the locking stud projecting from the sleeve, and for a positive and dependable lock with the locking stud.